#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <assert.h>

char* my_strcpy(char* destination, const char* source) {
	char* ret = destination;
	assert(destination);
	assert(source);
	while (*source) {
		*destination = *source;
		destination++;
		source++;
	}

	return ret;
}

int main() {
	char arr1[] = "abcdef";
	char arr2[20] = { 0 };
	char* ret = my_strcpy(arr2, arr1);
	printf("%s", ret);
	return 0;
}